00001 /*This file is prepared for Doxygen automatic documentation generation.*/ 00015 /* Copyright (c) 2009 Atmel Corporation. All rights reserved. 00016 * 00017 * Redistribution and use in source and binary forms, with or without 00018 * modification, are permitted provided that the following conditions are met: 00019 * 00020 * 1. Redistributions of source code must retain the above copyright notice, this 00021 * list of conditions and the following disclaimer. 00022 * 00023 * 2. Redistributions in binary form must reproduce the above copyright notice, 00024 * this list of conditions and the following disclaimer in the documentation 00025 * and/or other materials provided with the distribution. 00026 * 00027 * 3. The name of Atmel may not be used to endorse or promote products derived 00028 * from this software without specific prior written permission. 00029 * 00030 * 4. This software may only be redistributed and used in connection with an Atmel 00031 * AVR product. 00032 * 00033 * THIS SOFTWARE IS PROVIDED BY ATMEL "AS IS" AND ANY EXPRESS OR IMPLIED 00034 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 00035 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT ARE 00036 * EXPRESSLY AND SPECIFICALLY DISCLAIMED. IN NO EVENT SHALL ATMEL BE LIABLE FOR 00037 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES 00038 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 00039 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND 00040 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 00041 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS 00042 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE 00043 * 00044 */ 00045 00046 #include "dsp.h" 00047 00048 // Input angle from -pi/4 to pi/4 00049 dsp16_t dsp16_op_kernel_sinfix(dsp16_t angle) 00050 { 00051 // Coefficients of the 5th order Tchebychev polynom to calculate a sine. 00052 const dsp16_t s1 = DSP16_Q(0.785369873046875); 00053 const dsp16_t s3 = DSP16_Q(0.322784423828125); 00054 const dsp16_t s5 = DSP16_Q(0.03875732421875); 00055 S32 z, suma; 00056 00057 // Computation of the polynom 00058 z = (angle*angle) >> (DSP16_QB - 3); 00059 suma = s3 - ((z*s5) >> (DSP16_QB + 1)); 00060 suma = s1 - ((z*suma) >> (DSP16_QB + 1)); 00061 00062 return (angle*suma) >> (DSP16_QB - 2); 00063 } 00064 00065 // Input angle from -pi/4 to pi/4 00066 dsp32_t dsp32_op_kernel_sinfix(dsp32_t angle) 00067 { 00068 // Coefficients of the 13th order Tchebychev polynom to calculate a sinus. 00069 const dsp32_t S0 = DSP32_Q(0.78539816340); //pi/4; 00070 const dsp32_t S1 = DSP32_Q(-0.64596411675); //-1.6666667163e-01*pi^3/8; 00071 const dsp32_t S2 = DSP32_Q(0.31877052162); //8.3333337680e-03*pi^5/8; 00072 const dsp32_t S3 = DSP32_Q(-0.07490806720); //-1.9841270114e-04*pi^7/8; 00073 const dsp32_t S4 = DSP32_Q(0.01026823400); //2.7557314297e-06*pi^9/8; 00074 const dsp32_t S5 = DSP32_Q(-0.00092125426); //-2.5050759689e-08*pi^11/8; 00075 const dsp32_t S6 = DSP32_Q(0.00005769937); //1.5896910177e-10*pi^13/8; 00076 long long z, v, suma, produ; 00077 00078 // Computation of the polynom 00079 z = (long long) angle; 00080 z = (z*z) >> DSP32_QB; 00081 v = (long long) angle; 00082 v = (z*v) >> DSP32_QB; 00083 00084 produ = (z*S6) >> DSP32_QB; 00085 suma = S5 + produ; 00086 produ = (z*suma) >> DSP32_QB; 00087 suma = S4 + produ; 00088 produ = (z*suma) >> DSP32_QB; 00089 suma = S3 + produ; 00090 produ = (z*suma) >> DSP32_QB; 00091 suma = S2 + produ; 00092 00093 produ = (z*suma) >> DSP32_QB; 00094 suma = S1 + produ; 00095 produ = (v*suma) >> (DSP32_QB - 3); 00096 00097 return ((S0*((long long) angle)) >> (DSP32_QB - 2)) + produ; 00098 }